A silver halide photographic light sensitive material

Abstract: A silver halide photographic light-sensitive material is provided, comprising a support having thereon an antistatic layer and further having thereon a silver halide emulsion layer, wherein the antistatic layer comprises a water-soluble conductive polymer and a hydrophobic polymer, the layer having been hardened with a hardener, or the antistatic layer comprises conductive metal oxide particles containing at least one metal selected from Zn, Ti, Sn, Al, In, Si, Mg, Ba, Mo, W and V; and the silver halide emulsion is spectrally sensitized by adding thereto a substantially water-insoluble spectral-sensitizing dye in the form of a dispersion of solid particles dispersed in an aqueous medium substantially free from an organic solvent and a surfactant.

Description: The present invention relates to a silver halide photographic light-sensitive material improved in development uniformity, when subjected to rapid-processing, without deterioration of antistatic ability and a processing method thereof. Recently, rapid progress has been made in increasing the speed of processing and in decreasing the replenishing rate. As a result of these developments problems such as uneven development have arisen. It is known that uneven development may be prevented by accelerating the developing speed using a photographic material with an increased swelling degree. However, it has been found that this method results in deterioration in drying speed due to the increase of the water content. The addition of various surfactants has been attempted to solve uneven development but their effect was not sufficient. The present inventor has attempted the addition of a nonionic polyethylene-type surfactant for the purpose of preventing charging of the photographic material, however, uneven development was not avoided when the material was subjected to rapid-processing. EP-A-491176 discloses a silver halide photographic light-sensitive material said to be improved in anti-static ability, which comprises between its support and a back-coating layer, an anti-static layer consisting of a water-soluble conductive polymer, hydrophobic polymer particles and a hardener, or consisting of a metal oxide. The object of the present invention is to provide a silver halide photographic light-sensitive material capable of prohibiting occurrence of uneven development without deteriorating its antistatic ability. According to the present invention, there is provided a silver halide photographic light-sensitive material comprising a support which has, on at least one side, an antistatic layer comprising a water-soluble conductive polymer and a hydrophobic polymer that has been hardened with a hardener, or an antistatic layer which comprises conductive metal oxide particles comprising at least one metal selected from Zn, Ti, Sn, Al, In, Si, Mg, Ba, Mo, W and V; said antistatic layer having thereon a silver halide emulsion layer comprising a silver halide emulsion, which is spectrally sensitized by a substantially water-insoluble spectral sensitizing dye having a solubility in water of from 2x10 -4 to 4x10 -2 mol/l at 27°C in the form of a dispersion of solid particles having an average size of 1µm or less in an aqueous medium substantially free from an organic solvent and a surfactant. This dispersion is preferably obtainable by a process comprising adding said substantially water-insoluble spectral sensitizing dye, preferably in an amount in excess of the solubility thereof, into an aqueous medium substantially free from an organic solvent and a surfactant, and dispersing said dye. According to the invention there is further provided a method of processing the silver halide photographic light-sensitive material in an automatic processor in a total processing time (in other words, dry to dry time) of 20 to 60 seconds. Brief description of the Drawing Figure 1 shows a schematic view of an apparatus for use in the static mark test. Explanation of numerals 10: Neoprene rubber bar, 12: Sample, 13: Weight A technique of dispersing mechanically an organic dyestuff in aqueous medium has been described in Japanese Patent Open to Public Inspection (O.P.I.) No. 3-288842/1991. This technique is a means to immobilize a dye in a photographic material and is merely a method for introducing a dispersion. In contrast with this, the advantage of the present invention is that a spectral sensitizing dye is adsorbed uniformly and effectively on the surface of a silver halide grain. Thus it differs from the prior art technique for introducing a dispersion. An organic solvent generally means a solvent containing carbon atom(s) which is liquid at room temperature. As a solvent for a spectral sensitizing dye, there have been known water-miscible organic solvents such as alcohols, ketones, nitriles, and alkoxyalcohols. Examples thereof include methanol, ethanol, n-propylalcohol, isopropylalcohol, ethleneglycol, propyleneglycol, 1,3-propanediol, acetone, acetonitrile, 2-methoxyethanol and 2-ethoxyethanol. In the present invention, the term "substantially free from an organic solvent" generally means that an organic solvent, such as described above, is present in an amount preferably not more than 10%, more preferably 3%, more preferably 0.5% by weight. Known surfactants include anionic type surfactants, cationic type surfactants, nonionic type surfactants and betaine type surfactants. These surfactants are generally employed as dispersing agents for spectral sensitizing dyes. In the dispersion used in the present invention, however, these surfactants are substantially not present. Thus, in the present invention, the term "substantially free from a surfactant" means that the surfactant described above is present in an amount preferably not more than 0.10%, more preferably 0.05% by weight. The aqueous medium substantially free from an organic solvent and surfactant used in the present invention is preferably water containing no impurities capable of exerting a harmful effect, more preferably, it is deionized water. In order to disperse a spectral sensitizing dye in an aqueous medium which contains substantially no organic solvent or surfactant, various dispersion methods can be effectively employed. For example a high-speed stirrer, a ball mill, a sand mill, a colloid mill, an attritor, an ultrasonic dispersion machine may be used. In the present invention, a high-speed stirrer is preferred. Suitable high-speed stirrer type dispersing machines include a dispersing machine comprised of a dissolver fitted with a impeller. The high-speed stirrer type dispersing machine may optionally also be of the type having a dissolver comprising a vertical shaft to which a plurality of impellers are fitted or a multi-shaft dissolver provided with a plurality of vertical shafts. A high-speed sirring dipersion machine having an anchor blade is more preferable. In operation, for example, water is put in a temperature-controllable tank and thereafter a powder of spectral sensitizing dye is added in a given amount, followed by stirring using the high-speed stirrer for a given time under temperature control, and then pulverization and dispersion. There are no particular limitations on the pH and temperature when the spectral sensitizing dye is mechanically dispersed. If, however, the dispersion is carried out at a low temperature for a long time, the desired particle size may not be achieved, or if it is carried out at a high temperature, reagglomeration or decomposition may occur to make it impossible to obtain the desired photographic performance. Also, when the temperature is raised, the viscosity of a solution may decrease, lowering the pulverization of solids and dispersion efficiency. On account of these problems, the dispersion may be preferably carried out at a temperature of from 15 to 50°C. With regard to the stirring revolution rate when the dispersion is carried out, stirring at a low revolution rate may take a long time to achieve the desired particle size and stirring at an excessively high revolution rate may cause bubbles which decrease dispersion efficiency. Hence, the stirring may preferably be carried out at from 1,000 to 6,000 r.p.m. The dispersion used in the present invention is a solid particle dispersion (suspension) of a spectral sensitizing dye. The dispersion preferably contains the spectral sensitizing dye in an amount of from 0.2 to 5.0 % by weight. Solid particles of the dispersion preferably have an average size of 1 µm or less, more preferably, from 0.01 to 1.0 µm. The spectral sensitizing dye dispersion used in the present invention may be either directly added to the silver halide emulsion, or may be added after appropriate dilution. When diluted, water is used as a diluent. In the present invention, the term "substantially water-insoluble" generally means that the solubility of the spectral-sensitizing dye in water at 27 °C is from 2x10 -4 to 4x10 -2 , preferably from 1x10 -3 to 4x10 -2 mol per liter. If the solubility is lower than the above-mentioned preferred range, dispersed particle sizes may become so large as to be nonuniform. It has been found that as a result precipitates are produced in the dispersion formed. Thus the adsorption of the dye onto silver halide was hindered when such a dispersion was added to a silver halide emulsion. If the solubility is higher than the range, it has been found by the present inventors that the formation of the dispersion is hindered by the increase in the viscosity of the solution. The solubility of a spectral sensitizing dye in water is generally measured according to the following method. 30 ml of deionized water was poured into a 50 ml-Erlenmeyer flask, a dye was added thereto in an amount sufficient to remain undissolved under visual observation, and then the mixture was stirred with a magnetic stirrer for 10 minutes while being kept at 27°C in a thermostatic chamber. The resultant suspension was filtered with a Filter Paper No.2 (Toyo Filter Co., Ltd.), the filtrate was filtered with a disposable filter (Toso Co., Ltd.), the filtrate was diluted properly and subjected to measurement of absorbance using a U-3410 spectrophotometer (Hitachi Co., Ltd.). From the measurement results, the concentration of the solution was determined according to Lambert-Beer's law given by the following equation: D = εlc (D: absorbance, ε spectral absorption coefficient, 1: length of absorbance measuring cell, c: concentration), and then the solubilty was determined. A spectral sensitizing dye used in the invention is generally one which undergoes electron transfer to silver halide and resultingly contributes to the sensitization of silver halide when photo-excited when adsorbed on silver halide grains, ie such dyes do not include organic dyes. Spectral sensitizing dyes used in the invention may have any chemical structure as long as they are substantially water insoluble. Preferably their solubility in water is from 2x10 -4 to 4x10 -2 mol/liter. They are, more preferably, cyanine dyes. Suitable preferred cyanine dyes include those of the following formula (I). wherein Z 1 and Z 2 independently represent an nonmetallic atom group necessary for forming a 5- or 6-membered ring; R 1 and R 2 are independently a substituted or unsubstituted alkyl group; L 1 , L 2 and L 3 are independently a substituted or unsubstituted methine group; p and q are each independently 0 or 1; m is 0, 1, 2 or 3; X 1 represents an anion; and k is 0 or 1. More preferably, the cyanine dye is one substituted by a hydrophilic group such as -SO 3 H or -COOH. Examples are given below, wherein the solubility thereof in water is also shown in terms of mol per liter of water at 27'C. The dispersion of a spectral sensitizing dye used in the present invention may be added directly to a silver halide emulsion or added diluted by water. The amount added should exceed the solubility of the spectral sensitizing dye, and is preferably from 1 to 1000, more preferably, from 5 to 500 mg per mol of silver halide. Two or more kinds of dyes may be used in combination. Two or more dyes may be added as a mixture or separately at different times. The dyes may be added gradually in proportion to the surface area of the growing grains. The silver halide emulsion used in the invention may optionally be chemically sensitized. Examples of chemical-sensitization include sulfur sensitization, reduction sensitization, noble metal sensitization or a combination thereof. Examples of chemical sensitizers include sulfur sensitizers such as an allyl-thiocarbamide, thiourea, thiosulfate, thioether or cystein; noble metal sensitizers such as potassium chloroaurate, aurous thiosulfate or potassium chloropalladate; and reduction sensitizers such as tin chloride, phenylhydrazine or reductone. A silver halide photographic light sensitive material of the invention includes a silver halide emulsion layer, and optionally a hydrophilic colloidal layer such as a protective layer, an interlayer, a filter layer, a ultra-violet ray absorbing layer, an antistatic layer, a antihalation layer or a backing layer. Gelatin and various synthetic polymers can optionally be used, as a binder or protective colloid, for these hydrophilic colloidal layers. Besides lime-processed gelatin, there can be used acid-processed gelatin and gelatin derivatives as gelatin. Examples of synthetic polymers, include cellulose derivatives such as hydroxy-cellulose, polymers such as polyvinyl alcohol, polyvinyl alcohol partially acetal, poly-N-vinyl pyrrolidone, polyacrylate and polyacrylamide, and copolymers thereof. The compounds and materials generally used in the photographic materials of the invention are described in Research Disclosure (RD) Nos. 17643,18716 and 308119 (October, 1989) as below: Additives RD 17643 RD-18716 RD-308119 Page Sect. Page Page Sect. Desensitizing dye 23 IV 998 B Dye 25-26 VIII 649-650 1003 VIII Developing accelerator 24 XXI 648 Fog inhibitor Stabilizer 24 IV 649 1006-7 VI Brightener 24 V 998 V Hardener 26 X 651 1004-5 X Surfactant 26-27 XI 650 1005-6 XI Plasicizer 27 XII 650 1006 XII Sliding agent 27 XII Matting agent 28 XVI 650 1008-9 XVI Binder 26 XXII 1003-4 IX Support 28 XVII 1009 XVII Suitable supports for use in the silver halide photographic light sensitive material of the present invention are described in the above-mentiond Research Disclosures. An appropriate support is a plastic film. The surface of the support may be provided with a subbing layer so as to improve adhesion, or subjected to corona dischare or ultra-violet ray irradiation. The processing steps of a silver halide photographic light sensitive material of the invention are preferably completed within a period of 90 seconds or less, when processed with an automatic processor including the steps of developing, fixing, washing (or stabilizing) and drying. Thus, the period of time from when the top of a photographic material is dipped into a developer to when the top of the material exits the drying zone (so-called dry to dry time) is preferably within 60 seconds, more preferably within 45 seconds. The fixing time and temperature are preferably from 6 to 20 seconds to from 20 to 50°C, more preferably from 6 to 15 seconds ar from 30 to 40°C. The developing time with a developer is preferably from 5 to 45 seconds, preferably from 8 to 30 seconds. The developing temperature is preferably from 25 to 50°C, more preferably from 30 to 40°C. The drying zone preferably has a heating means comprising blowing heated air at a temperature of from 35 to 100°C, preferably from 40 to 80°C or comprising exposing the material to a far-infrared source. The drying zone may optionally be built into an automatic processor. The automatic processor may optionally be provided with a device capable of supplying water or a acidic rinsing solution having no fixing abilty between developing and fixing,or between fixing and washing. The processor may also optionally be provided with equipment capable of preparing developer or fixer solutions. The photographic material of the present invention can optionally be processed with a processing solution as described in Research Disclosures RD-17643, XX-XXI on pages 29-30 and RD-308119, XX-XXI on pages1011-1012. As the developer for black and white photographic processing, dihydroxybenzenes such as hydroquinone, 3-pyrazolidones such as 1-phenyl-3-pyrazolidone, aminophenols such as N-methyl-p-aminophenol or a combination thereof can optionally be used. In addition, the developer may contain, according to need, a preservative, alkaline agent, pH buffer, antifoggant, hardener, development accelerating agent, surfactant, deformer, toning agent, water-softening agent, solubilizing aids or thickener, as conventionally known in the art. Furthermore, the developer replenishing amount used is preferably not more than 300 ml/m 2 . A fixing agent such as a thiosulfate or thiocyanate can generally be used in the fixing solution. In addition a water-soluble aluminium salt such as aluminium sulfate or potassium alum may optionally be contained. Also a preservative, pH-adjusting agent or water-softening agent may optionally be included. The antistatic layer which is used in the present invention is chosen from (1) and (2) set out below: (1) An antistatic layer containing a water soluble electrically-conducting polymer and a hydrophobic polymer, the layer having been hardened by adding thereto a hardener, which is described in JP O.P.I. No.6-130527. Examples of water-soluble conductive polymers are given as follows. In the above polymers, M represents the weight-average molecular weight. The water-soluble conductive polymer used in the invention is preferably present in an amount of from 0.001 to 10 g, preferably 0.05 to 5 g per m 2 of a photographic material. Examples of hydrophobic polymers are given below. In the above polymers, M represents the weight-average molecular weight. The hydrophobic polymer is preferably present in an amount of from 5 to 60%, more preferably from 10 to 40% based on the weight of the water-soluble conductive polymer. Examples of the hardener used in the present invention are given below. Aziridines represented by the following formula, wherein R 1 is a hydrogen atom, an alkyl group having 20 or less carbon atoms, an aryl group, hydroxy, or halogen atom; R 2 is a hydrogen atom or an alkyl group having 10 or less carbon atoms. Examples of aziridines include: Examples of α-Cyanoacrylates suitable for use as the hardener include: Examples of Epoxides suitable for use as the hardener include: The hardener as described above is preferably dissolved in water or in an organic solvent such as an alcohol or acetone, either added as such or with a surfactant. The hardener is preferably added in an amount of from 1 to 1000 mg/m 2 of a photographic material. The antistatic layer which is used in the invention may also be : (2) An antistatic layer comprising conductive metal oxide particles containing at least metal selected from Zn, Ti, Sn, Al, In, Si, Mg, Ba, Mo, W, and V, as described in JP O.P.I. No. 4-234756. Examples of the metal oxide particles include ZnO, TiO 2 , SnO 2 , Al 2 O 3 , In 2 O 3 , SiO 2 , MgO, BaO, MoO 3 , V 2 O 5 and complexes thereof. Among them, ZnO, TiO 2 and SnO 2 are preferable. The metal oxide is preferably contained in an amount of from 0.0009 to 0.5 g/m 2 , preferably, from 0.0012 to 0.3 g/m 2 of photographic material. In the embodiment of the present invention, various techniques which are known in the photographic technology can be applied. Example 1 Preparation of tabular seed emulsion A tabular,hexagonal crystal seed emulsion was prepared in the following manner. Solution A Ossein gelatin 60.2 g Distilled water 20.0 l Polyisopropylene-polyethylene-disuccinate sodium salt (10% ethanol solution) 5.6 ml KBr 26.8 g 10% H 2 SO 4 144 ml Solution B Silver nitrate 1487.5 g Distilled water to make 3500 ml Solution C KBr 1029 g KI 29.3 g Distilled water 3500 ml Solution D 1.75 M. KBr solution, i.e. an amount necessary to control the Ag-potential 64.1 ml of each of Solutions B and C was simultaneously added to solution A at a temperature of 35°C by a double jet method over a period of two minutes, while stirred by a mixing stirrer as disclosed in JP Examined Nos. 58-58288 and 58-58289 so that nucleus grains were formed. After completing the addition of solutions B and C, the temperature of the mother liquor was increased to 60°C over 60 minutes and the remaining solutions A and B were added thereto at a flow rate of 68.5 ml/min. over a period of 50 minutes, while the silver potential which was monitored by a silver ion selection electrode with reference to a saturated silver-silver chloride electrode was controlled to be +6 mV using Solution D. After completing the addition, the pH of the resulting emulsion was adjusted to 6 using a 3% KOH solution and subjected to desalinization-washing to obtain a seed emulsiom EM-A. Thus prepared seed emulsion EM-A comprised haxagonal tabular gains having an maximun adjacent edge ratio and accounting for 90% of the total projected area, which were found to have an average thickness of 0.07 µm and an average size (circle-equivalent diameter) of 0.5 µm by observation with an electron microscope. Preparation of monodispersed twinned crystal grain emulsion A monodispersed, twinned crystal silver iodobromide emulsion containing 1.5 mol% iodide on average was prepared using the following solutions. Solutions of B1 and C1 were simultaneously added into Solution Al at 60°C by a double jet method using a mixing stirrer disclosed in JP Examined Nos. 58-58288 and 58-58289. During addition thereof, the silver potential of the mother liquor was controlled to be +25 mV using Solution D1. After completing the addition, the resulting emulsion was subjected to precipitating desalinization to remove excess salts using aqueous solutions of Demol (produced by Kao-Atlas) and magnesium sulfate, and then 2500 ml of a gelatin solution containing 92.2 g of gelatin was added thereto to redisperse the emulsion. The thus prepared emulsion contains 1.53 mol% iodide on average, has an average grain size of 1.05 µm which is the diameter of a circle equivalent in area to that of the projected image of the grain and an average thickness of 0.25 µm; and 90% of the projected area of the total grains have a ratio of grain diameter to thickness of 2 or more and the standard deviation of the ratio of grain diameter/ an average diameter is 0.22. To the emulsion EM-1, were added spectral sensitizing dyes I-1 and I-2 which were dispersed according to the following methods D-1 to 4, in an amount as shown in Table 1. The resulting emulsions were each chemically sensitized by adding 2.4x10 3 mol/mol Ag of ammonium thicyanate and optimal amounts of a chloroaurate and sodium thiosulfate, and thereafter were stabilized by adding 2x10 -2 mol of 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene. The sensitizing dyes were dispersed using a high speed stirring type disperser. D-1: The sensitizing dyes I-1 and I-2 (9.87 g : 0.13 g) were dissolved in methanol at 27°C to obtain a dye methanol solution. D-2: The sensitizing dyes I-1 and I-2 (9.87 g : 0.13 g) were added to a mixed solution of 4.9 g of methanol and 485.1 g of water which was previously adjusted to a temperature of 27°C and then the mixture was stirred with a high speed stirrer (Dissolver) at 3,500 rpm over a period of 30 to 120 minutes to obtain a spectral sensitizing dye dispersion. D-3: The sensitizing dyes I-1 and I-2 (9.87 g : 0.13 g) were added to 490 g of an aqueous solution containing 0.1% triisopropylnaphthalene sulfonic acid which was previously adjusted to a temperature of 27°C and then the mixture was stirred with a high speed stirrer (Dissolver) at 3,500 rpm over a period of 30 to 120 minutes to obtain a spectral sensitizing dye dispersion. D-4: The sensitizing dyes I-1 and I-2 (9.87 g : 0.13 g) were added to 490 g of water which was previously adjusted to a temperature of 27°C and then the mixture was stirred with a high speed stirrer (Dissolver) at 3,500 rpm over a period of 30 to 120 minutes to obtain a spectral sensitizing dye dispersion in a form of solid particle dispersion. Various additives were added as follows. Additives which were added to the emulsion (silver halide coating solution) are as follows. The addition amount was expressed in terms of mol per mol of silver halide. Additives used in the protective layer coating solution were as follows. Amounts thereof were expressed in terms of per g of gelatin. An antistatic agent was added in an amount as shown in Table 1 Coating solutions as above were each coated on both sides of a subbed and blue-colored polyethylene terephthalate film base having a thickness of 180 µm. The silver coverage and gelatin contents of the emulsion and protective layers were 1.8 g/m 2 , 1.8 g/m2 and 1.0 g/m 2 , respectively, each expressed in terms of an amount per side. An interlayer described in Table 1 was provided between a subbing layer and an emulsion layer. Samples were evaluated in the following manner and the results thereof were shown in Table 1. Surface electric resistance: A test piece of each sample was sandwiched with brass-made electrodes, 10 cm in length and having an electrode spacing of 14 cm, and the resistance thereof was measured with a insulation-meter produced by Takeda Riken Co., Type TR 8651 over a period of one minute. Samples, after being aged for two hours under a temperature of 25°C and a relative humidity of 20%, were subjected to the measurement. Development evenness: Samples were each exposed uniformly to tungsten light so as to produce a density of 1.5 ± 0.2, and processed with SRX-503 (product of Konica), in which the 45 second mode was changed to a 30 second mode (line-speed was increased by modification). The resulting samples were visually evaluated with respect to development evenness, based on the following five grades. 5: Excellent, 4: Good, 3: No problem in practical use, 2: Deteriorated, 1: Poorly deteriorated Sample Sensitizing dye Antistatic agent Processing time (sec.) Surface resistance (Ω/cm) Development unevenness Remark Kind Amount Kind Layer Amount 1 D-1 370 - - - 45 no less than10 4 4 Comp. 2 D-1 370 A PL 65 45 5x10 11 1 Comp. 3 D-4 370 A PL 65 45 5x10 11 2 Comp. 4 D-4 370 B PL 65 45 6x10 11 2 Comp. 5 D-4 370 C PL 65 45 1x10 13 2 Comp. 6 D-1 370 P IL 600 45 1x10 11 2 Comp. 7 D-3 370 P IL 600 45 1x10 11 2 Comp. 8 D-4 370 P IL 600 45 1x10 11 4 Inv. 9 D-1 370 S IL 170 45 2x10 10 2 Comp. 10 D-4 370 S IL 170 45 2x10 10 4 Inv. 11 D-4 370 I IL 170 45 1.3x10 10 4 Inv. 12 D-1 370 A PL 65 30 5x10 11 1 Comp. 13 D-1 370 P IL 600 30 1x10 11 1 Comp. 14 D-4 370 P IL 600 30 1x10 11 4 Inv. 15 D-4 370 S IL 170 30 2x10 10 4 Inv. Inventive antistatic layer expressed in terms of "P" in the table contained compounds as below. From the results in Table 1, samples containing an inventive silver halide emulsion were shown to be low in surface resistance and improved in development unevenness, even when rapid-processed. Example 2 Preparation of silver halide emulsion: On monodisperse silver iodobromide nucleus grains having an average size of 0.2 µm and an average iodide content of 2.0 mol%, silver iodobromide containing 30 mol% iodide was further grown at a pH of 9.8 and a pAg of 7.8, thereafter, equimolar amounts of potassium bromide and silver nitrate were added thereto to form monodisperse silver iodobromide grains having an average iodide content of 2.2 mol% and an average size of 0.395 µm. The emulsion formed was desalted by a coagulation method to remove excessive salts. Thus, a solution of a condensation product of formalin with naphthalene sulfonic acid sodium salt and a solution of magnesium sulfate were added to the emulsion to form coagulum. After removing the supernatant, water (40°C) was added thereto to disperse the coagulum, and then the resultant emulsion was again coagulated by adding a magnesium sulfate solution to remove the supernatant. The thus obtained silver halide grain emulsion was proved to be excellent in monodispersity having a monodispersity degree of 0.15. Preparation of samples, and processing and evaluation thereof. To the emulsion prepared as above, water was added to make a volume of 500 ml per mol of silver halide. After adjusting the temperature to 55°C, spectral sensitizing dyes I-1 and I-2 (200:1 by weight), which were dispersed in the same manner as in D-1 and D-4 of Example 1, were added to the emulsion in a total amount of 300 mg permol of silver halide. After 10 minutes, the emulsion was chemically sensitized by adding 2.6x10 -3 mol/mol Ag of ammonium thiocyanate and optimal amounts of a chloroaurate and sodium thiosulfate. During this time, the pH and silver potential were maintained at 6.15 and 50 mV, respectively. At 15 minutes before the completion of the chemical sensitization (at 70 minutes after the start of the chemical sensitization), 200 mg/mol Ag of potassium iodide was added thereto. After 5 minutes, an acetic acid solution (10% wt./vol.) was addded to lower the pH to 5.6 and the pH was maintained at this level for 5 minutes. Thereafter, the pH of the emulsion was increased to 6.15 by adding a potasium hydroxide solution (0.5% wt./vol.), then 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene was added to stop the chemical sensitization and a photographic emulsion was obtained. The thus obtained emulsion was found to have a pH of 6.10 and a silver potential of 81 mV at 35°C. Using an emulsion coating solution and protective layer coating solution as shown below, photographic samples were prepared so that an emulsion layer was coated so as to have a gelatin content of 1.6 g/m 2 and a silver coverage of 3.0 g/m 2 and a protective layer was coated thereon so as to have 0.9 g/m 2 of gelatin. Spectral sensitizing dyes were added as shown in Table 2. Antistatic layers on the emulsion layer-side and backing layer-side, as shown in Table 2, were coated in the same manner as in Example 1. Additives used in the emulsion layer (silver halide emulsion coating solution) were as follows, where the amount added is expressed in terms of the amount per mol of silver halide. 1,1-Dimethylol-1-brom-1-nitromethane 70 mg t-Butyl-catechol 400 mg polyvinyl pyrrolidone (M.W.: 10,000) 1.0 g Styrene-anhydrous maleic acid copolymer 2.5 g Trimethylol propane 10 g Diethylene glycol 5 g Nitrophenyl-triphenyl-phosphonium chloride 50 mg Ammonium 1,3-dihydroxybenzene-4-sulfonate 4 g Sodium 2-mercaptobenzimidazole-5-sulfonate 1.5 mg Compound N 150 mg Compound S 70 mg n-C 4 H 9 OCH 2 CH(OH)CH 2 N(CH 2 COOH) 2 1 g Compounds N and S are the same as those of Example 1. Additives used in the protective layer are as follows, where the amount added is expressed in terms of an amount per liter of the coating solution. Lime-processed inert gelatin 68 g Acid-processed gelatin 2 g Polymethylacrylate (matte material having an area-averaged particle size of 3.5 µm) 1.1 g Silicon dioxide particles (matte material having an area-averaged size of 1.2 µm) 0.5 g Ludox AM (colloidal silica produced by du Pont) 30 g 2% solution of 2,4-Dichloro-6-hydroxy-1,3,5-triazine sodium salt 12 ml Sodium i-amyl-n-decylsulfosuccinate 1.0 g C 8 F 17 SO 3 K 0.2 g Antistatic agent, as shown in Table 2 Backing layers were coated using the following compositions. An interlayer as an antistatic layer, as shown in Table 2, was coated between a lower backing-layer and a subbing layer. Backing layers were coated, having the following compositions where amounts are expressed as an amount per liter of a coating solution. Lower backing-layer: Upper backing-layer (Protective layer): (per liter of coating solution) Lime-processed gelatin 70 g Acid-processed gelatin 5 g Trimethylolpropane 1.5 g Backing dye A 2.0 g Backing dye B 2.0 g KNO 3 2% solution of 2,4-Dichloro-6-hydroxy-1,3,5-triazine sodium salt 12 ml Polymethylmethaacrylate particles having a area-averaged particle size of 4.0 µm 1.1 g Sodium diethylhexylsulfosuccinate 0.4 g Antistatic agent(s), as shown in Table 2 Lower and upper backing-layers were respectively coated so that gelatin coating amounts thereof were 1.6 and 0.9 g/m 2 . Thus-prepared samples were evaluated in the same manner as in Example 1, except that static marks were visually observed to evaluate the antistatic property. Results thereof are shown in Table 2. Evaluation of static mark: Samples were kept standing in an atmosphere with a temperature of 23°C and a relative humidity of 20% over a period of one hour, thereafter, they were cut into 6x30 cm pieces. As illustrated in Fig.1, a weight of 500 g was suspended on each piece which was subjected to friction with neoprene rubber rod of about 30 mm in diameter at a speed of one reciprocal cycle per about 0.8 seconds in the direction indicated by an arrow in a total of five cycles. Then, the piece, remaining unexposed, was processed using an automatic processor SRX-501 (product of Konica), and macroscopically observed for static marks. The antistatic property was evaluated in accodance with the following criteria. 5: Excellent, 4: Good, 3: No problem in practical use, 2: Deteriorated, 1: Poorly deteriorated. Sample No. Sensitizing dye Antistatic agent (EC ) Antistatic agent (BC ) Processing time (sec.) static marks Development unevenness Remark Kind Amount Kind Layer Amount Kind Layer Amount 1 D-1 370 A PL 65 A PL* 65 30 4 1 Comp. 2 D-4 370 - - - A PL* 65 30 1 3 Comp. 3 D-4 370 P IL 600 P IL* 600 30 5 4 Inv. 4 D-4 370 - - - P IL* 600 30 3 4 Inv. 5 D-4 370 - - - S IL* 170 30 4 4 Inv. As can be seen from the results of Table 2, it was proved that inventive samples had less static marks and were improved in development unevenness, when subjected to rapid processing.

Claims: A silver halide photographic light-sensitive material comprising a support which has, on at least one side, an antistatic layer comprising a water-soluble conductive polymer and a hydrophobic polymer that has been hardened with a hardener, or an antistatic layer which comprises conductive metal oxide particles comprising at least one metal selected from Zn, Ti, Sn, Al, In, Si, Mg, Ba, Mo, W and V; wherein said antistatic layer is coated with a silver halide emulsion layer comprising a silver halide emulsion, which is spectrally sensitized by a substantially water-insoluble spectral-sensitizing dye having a solubility in water of from 2x10 -4 to 4x10 -2 mol/l at 27°C, in the form of a dispersion of solid particles having an average size of 1 µm or less, in an aqueous medium substantially free from an organic solvent and a surfactant. The silver halide photographic material of claim I, wherein said antistatic layer comprises conductive metal oxide particles selected from ZnO, TiO 2 , SnO 2 , Al 2 O 3 , In 2 O 3 , SiO 2 , MgO, BaO, MoO 3 , V 2 O 3 , and complexes thereof. The silver halide photographic material of claim 1 or 2, wherein said dye is dispersed in water. The silver halide photographic material of claims 1, 2 or 3, wherein said dispersion is obtainable by a process comprising adding said dye in the form of fine particles having an average size of 1 µm or less into the aqueous medium substantially free from an organic solvent and surfactant, and dispersing said dye. A method of processing the silver halide photographic material according to any one of the preceding claims, wherein the material is processed in an automatic processor in a total processing time of from 20 to 60 seconds.

Inventors: TSUJI NOBUAKI, TSUJI, NOBUAKI
Applicants: KONISHIROKU PHOTO IND, KONICA CORPORATION
Application year: 1994
Main classification: G03C1
IPC codes: G03C1